Air conditioning system utilizing refrigeration



Jlme 1942- c. o. BERGSTROM 2,286,252

AIR CONDITIONING SYSTEM UTILIZING REFRIGERATION v 2- Sheets-Sheet 1Original Filed July 13, 1939 1 m IHIIJ l 1 INVENTOR.

C424. 0. Bzzssrepm I @ami J M ATTORNEY.-

June 16, 1942. c; o. BERGSTROM 2,286,252

AIR CONDITIONING SYSTEM UTILIZING REFRIGERATION Original Filed July 13,1959 2 Sheets$heet 2 EvAPoRA TOR ELECTRIC SOURCE INVENTOR. CARL 0.Bazaar-20M ATTORNEY.

, Patented June 16, 1942 AIR CONDITIONING SYSTEM UTILIZING REFRIGERATIONCarl O. iBergstrom, Boston, Mass, assignor to B. F. Sturtevant Company,Boston, Mass.

Original application July 13, 1939, Serial No.

284,262, now Patent No. 2,258,565, dated Octoher 7, 1941. Divided andthis application May 8, 1940, Serial No. 333,918

3 Claims. (Cl. 98-10) This invention relates to air conditioning systemsfor passenger vehicles, utilizing refrigeration and has as its object tosave in refrigeration when outdoor conditions are right for effectivecooling to be accomplished through supplying an increased volume ofoutdoor air.

This application is a division of my copending application, Serial No.284,262 filed July 13, 1939, now Patent No. 2,258,565, October 7, 1941.

On. some railroad lines, it is possible to affect suflicient cooling, insummer, by forcing large volumes of outdoor air through the cars. Thereare brief periods, however, on such lines when a relatively small amountof refrigeration for cooling is desired. This invention providesefficient apparatus at low cost for combining refrigerative cooling withpressure ventilation under effective thermostatic control.

The invention will now be described with reference to the drawings, ofwhich:

Fig. l is a plan view looking downwardly upon a railway passenger carembodying this invention, with a portion of the roof removed, and aportion in section;

Fig. 2 is an elevation view with a portion of the side removed, and aportion in section of the passenger car of Fig. 1;

Fig. 3 is a sectional view along the lines 33 of Fig. 2, and

Fig. 4 is a diagrammatic view of the automatic controls employed.

The car 5 has the longitudinal duct 6 mounted in the roof zone above theceiling. The lower wall of this duct may form the ceiling of the car.The lower wall of the duct is perforated to receive the centrifugal fansI which extend into the passenger space and which are fitted withhorizontal deflectors I5 for discharging air in horizontal streams intothe passenger space. The fans preferably employed are those of my PatentNo. 2,142,834 which issued Jan. 3, 1939.

The two air cooling evaporators 8 are mounted in the duct 6 adjacent thelongitudinal center inlets II could of course, be arranged in the endsor sides of the duct.

thereof, one on each side of the recirculated air inlet 9, which is inthe lower wall of the duct at the longitudinal center thereof. Thedampers I0 are adjustable as will be explained later, to control thevolume of recirculated air.

The duct 6 contains in its upper wall, the fresh air inlets II withdampers I2. The ventilators I3 which contain the air filters I4 are inthe sides of the car and supply outdoor air which passes along the sideof and top of the duct and enters the inlets I I under the suction ofthe fans I. The

Referring now to Fig. 4; the thermostat I6 which may be mounted in theoutdoor air stream or in the passenger space, controls the conversionfrom pressure to refrigerative cooling and vice versa. By way ofexample, when the temperature of the outdoor air is below say F., thecontacts of the thermostat I6 are open and the relays I1 and I8 and thecompressor motor are deenergized through being disconnected from theelectric source 20. The contacts of the relay II are closed and completethe electric circuit including the electric source 20, the wires 2 I,22, 23, 24, 25 and 26 and the dampermotors 21, causing the. motors 21 toadjust the fresh outdoor air dampers I2 to full open position. At thistime,

the contacts of the relay I8 are open causing the electric circuitincluding the electric source 20, the wires 23, 22, 3|, the recirculatedair damper motor 30, the wires 29, the contacts of the relay I2, and thewires 28, 25 and 24 to be deenergized. This causes the motor 30 toadjust the recirculated air dampers to fully closed position. At thesame time, the compressor motor I9'is deenergized due to the contacts ofthe thermostat I6 which are in series with it and the electric source20, being separated.

Thus when the temperature of the outdoor air is below 80 F., thecompressor 32 which in cooperation with the condenser 33 and theexpansion valve 34, supplies the evaporators 8 with refrigerant, is shutdown, and the fans I draw in, for example 4200 cubic feet per minute ofoutdoor air through the inlets II and I3, and supplyit into thepassenger space.

, When the temperature of the air rises above- 80 F., the, thermostat I6closes its contacts; the

solenoids of the relays I! and I8 are energized with the result that thedamper motors adjust the outdoor air dampers to closed or substantiallyclosed positions; the damper motor 30 adjusts the recirculated airdampers III to wide open position, and the compressor motor I9 isenergized to drive the compressor 32.

The fans I now operate against a, higher pressure which reduces the airvolume to about 2,000 cubic feet of air :per minute. There will be aleakage through the fresh air dampers I2 providing about 25% of outdoorair. The recirculated air through the inlet 0 passes through theevaporators 8, is mixed inthe duct i with they outdoor air and thendischarged into the passenger space.

This design provides a relatively inexpensive 1. An air cooling systemfor a passenger vehicle comprising a longitudinal duct overhead thepassenger space, means for admitting outdoor air at a plurality ofpoints into said duct, means ior admitting air from the passenger spaceinto said duct adjacent the longitudinal center thereof, said ducthaving a plurality oi longitudinally spaced apertures in its lower wall,and a plurality of fans communicating with said duct through saidapertures and with the passenger space for drawing outdoor air throughsaid first mentioned means and recirculated air through said secondmentioned means and for discharging it, into the passenger space.

2. An air cooling system for a passenger vehiclecomprising alongitudinal duct overhead the passenger space, means for admittingoutdoor air at a plurality of points into said duct, means for admittingair from the passenger space into said ductadjacent the longitudinalcenter thereof, air cooling means in said duct adjacent the longitudinalcenter thereof in the path of the recirculated air admitted through saidlast mentioned means, said duct having a plurality of longitudinallyspaced apertures in its lower wall, and a plurality of fanscommunicating with said duct through said apertures and with thepassenger space Iordrawing outdoor air through said first mentionedmeans and recirculated air through said second mentioned means and fordischarging it into the passengerspace.

3. An air cooling system for a passenger vehicle comprising alongitudinal duct overhead the passenger space, means for admittingoutdoor air at a plurality 01' points into said duct. means foradmitting air from the passenger space into said duct adjacent thelongitudinal center thereof, air coolingmeans in said'duct on oppositesides of said last mentioned means in the path 01 the recirculated airadmitted therethrough,

said duct having a plurality of longitudinally spaced apertures in itslower wall, and a plurality of fans communicating with said duct throughsaid apertures and with the passenger space for drawing outdoor airthrough said first mentioned means and recirculated air through saidsecond i mentioned means and tor discharging it into the passengerspace.

CARL O. BERGSTROM.

